Use proto from newer locations, and go mod tidy (google#863)

Author: mhutchinson

cloudbuild.yaml

@@ -70,8 +70,8 @@ steps:
     - '-ec'
     - |
       go install \
-        google.golang.org/protobuf/proto \
-        google.golang.org/protobuf/cmd/protoc-gen-go \
+        github.com/golang/protobuf/proto \
+        github.com/golang/protobuf/protoc-gen-go \
         github.com/golang/mock/mockgen \
         go.etcd.io/etcd/v3 go.etcd.io/etcd/etcdctl/v3 \
         github.com/fullstorydev/grpcurl/cmd/grpcurl

cloudbuild_master.yaml

@@ -70,8 +70,8 @@ steps:
     - '-ec'
     - |
       go install \
-        google.golang.org/protobuf/proto \
-        google.golang.org/protobuf/protoc-gen-go \
+        github.com/golang/protobuf/proto \
+        github.com/golang/protobuf/protoc-gen-go \
         github.com/golang/mock/mockgen \
         go.etcd.io/etcd/v3 go.etcd.io/etcd/etcdctl/v3 \
         github.com/fullstorydev/grpcurl/cmd/grpcurl

cloudbuild_tag.yaml

@@ -70,8 +70,8 @@ steps:
     - '-ec'
     - |
       go install \
-        google.golang.org/protobuf/proto \
-        google.golang.org/protobuf/protoc-gen-go \
+        github.com/golang/protobuf/proto \
+        github.com/golang/protobuf/protoc-gen-go \
         github.com/golang/mock/mockgen \
         go.etcd.io/etcd/v3 go.etcd.io/etcd/etcdctl/v3 \
         github.com/fullstorydev/grpcurl/cmd/grpcurl

go.mod

@@ -9,10 +9,10 @@ require (
 	github.com/golang/protobuf v1.5.2
 	github.com/google/go-cmp v0.5.6
 	github.com/google/trillian v1.4.0
-	github.com/gorilla/mux v1.8.0 // indirect
+	github.com/gorilla/mux v1.8.0
 	github.com/juju/ratelimit v1.0.1
 	github.com/kylelemons/godebug v1.1.0
-	github.com/mattn/go-sqlite3 v1.14.8 // indirect
+	github.com/mattn/go-sqlite3 v1.14.8
 	github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826
 	github.com/prometheus/client_golang v1.11.0
 	github.com/rs/cors v1.8.0
@@ -25,5 +25,5 @@ require (
 	golang.org/x/net v0.0.0-20210503060351-7fd8e65b6420
 	google.golang.org/grpc v1.40.0
 	google.golang.org/protobuf v1.27.1
-	gopkg.in/yaml.v2 v2.4.0 // indirect
+	gopkg.in/yaml.v2 v2.4.0
 )